https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92174
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Steve Kargl from comment #3) > On Tue, Oct 22, 2019 at 02:14:55PM +0000, marxin at gcc dot gnu.org wrote: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92174 > > > > --- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> --- > > (In reply to kargl from comment #1) > > > (In reply to Martin Liška from comment #0) > > > > Happens with UBSAN build in: > > > > > > > > $ ./xgcc -B. > > > > /home/marxin/Programming/gcc/gcc/testsuite/gfortran.dg/pr91802.f90 > > > > -fcoarray=single > > > > ../../gcc/fortran/array.c:867:36: runtime error: index 15 out of bounds > > > > for > > > > type 'gfc_expr *[15]' > > > > > > > > > What are you doing? pr91802.f90 is a compile time test. > > > It cannot generate a runtime error. > > > > It's a runtime error of the GCC compiler that compiles the test-case ;) > > The error message is a bit misleading. > > > > So, what does your tool do? gfortran correctly diagnosis > that rank+corank > 15, issues an error, and exits. What is > the problem? Problem is that the compiler invokes an undefined behaviour for the source file. You can see the same with the following patch: diff --git a/gcc/fortran/array.c b/gcc/fortran/array.c index 427110bee74..166caca8347 100644 --- a/gcc/fortran/array.c +++ b/gcc/fortran/array.c @@ -864,6 +864,7 @@ gfc_set_array_spec (gfc_symbol *sym, gfc_array_spec *as, locus *error_loc) sym->as->corank = as->corank; for (i = 0; i < as->corank; i++) { + gcc_assert (sym->as->rank + i < GFC_MAX_DIMENSIONS); sym->as->lower[sym->as->rank + i] = as->lower[i]; sym->as->upper[sym->as->rank + i] = as->upper[i]; } $ ./xgcc -B. /home/marxin/Programming/gcc/gcc/testsuite/gfortran.dg/pr91802.f90 -fcoarray=single f951: internal compiler error: in gfc_set_array_spec, at fortran/array.c:867 0x880e62 gfc_set_array_spec(gfc_symbol*, gfc_array_spec*, locus*) /home/marxin/Programming/gcc/gcc/fortran/array.c:867 0x8b3f6d attr_decl1 /home/marxin/Programming/gcc/gcc/fortran/decl.c:8521 0x8b4114 attr_decl /home/marxin/Programming/gcc/gcc/fortran/decl.c:8582 0x8b46f0 gfc_match_codimension() /home/marxin/Programming/gcc/gcc/fortran/decl.c:8855 0x93dd54 match_word /home/marxin/Programming/gcc/gcc/fortran/parse.c:65 0x93efcb decode_statement /home/marxin/Programming/gcc/gcc/fortran/parse.c:464 0x944185 next_free /home/marxin/Programming/gcc/gcc/fortran/parse.c:1272 0x944727 next_statement /home/marxin/Programming/gcc/gcc/fortran/parse.c:1504 0x947bf0 parse_spec /home/marxin/Programming/gcc/gcc/fortran/parse.c:3902 0x94b747 parse_module /home/marxin/Programming/gcc/gcc/fortran/parse.c:6085 0x94c15b gfc_parse_file() /home/marxin/Programming/gcc/gcc/fortran/parse.c:6390 0x9ad167 gfc_be_parse_file /home/marxin/Programming/gcc/gcc/fortran/f95-lang.c:208 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. Note that sym->as->lower is defined as: struct gfc_expr *lower[GFC_MAX_DIMENSIONS], *upper[GFC_MAX_DIMENSIONS]; Hope it's clear now? Thanks.
